Good evening! Girls, at what months did your babies start teething? We…

Good evening! Girls, at what months did your babies start teething? We're almost 4 months old, a couple of days ago the temperature rose to 39, we gave him ibuprofen, called a doctor home and they said it was a virus, his throat is red and conjunctivitis, for teeth still too early. The next day there was no fever, but saliva by the river, constantly putting hands in his mouth, scratching nose, eyes, nervous, gums not swollen. I don't understand if this is all a virus or gums?